Mermaid weed

Care at a glance

Overview

A stem plant for the midground that needs strong light and benefits a lot from CO2 to develop its prized orange-to-red feathery submersed leaves; in low light and no CO2 it stays green and grows poorly. Plant stems individually with room around them in a nutrient-rich substrate, and be patient because freshly imported emersed plants take weeks to convert to the submersed form. It is a moderate grower with few side shoots, so propagate by topping and replanting the cuttings.

In the wild

Found in swamps, ditches, pond margins and seasonally flooded ground throughout the eastern and southern United States, the Caribbean islands, and parts of Central and South America. It grows as an emersed marsh plant with feathery toothed leaves and switches to a different leaf form when kept submerged.

Good to know

A member of the watermilfoil family Haloragaceae. The plant is strongly heterophyllous: emersed it makes simple toothed lance-shaped leaves, while submersed it develops finely divided comb-like (pectinate) leaves that can colour orange-red. The 'Cuba' form that brought it to popularity was imported by Tropica.

Did you know

Did you know the emersed and submersed leaves look so different that growers sometimes think they were sold the wrong plant? The above-water form has plain saw-toothed leaves, while underwater it transforms into delicate fern-like combs that flush orange under bright light.

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